This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH v2 1/9] Add configure check to test if gcc supports attribute ifunc.
- From: "Paul E. Murphy" <murphyp at linux dot vnet dot ibm dot com>
- To: Stefan Liebler <stli at linux dot vnet dot ibm dot com>, libc-alpha at sourceware dot org
- Cc: fweimer at redhat dot com, schwab at linux-m68k dot org, joseph_myers at mentor dot com
- Date: Mon, 8 Aug 2016 11:08:29 -0500
- Subject: Re: [PATCH v2 1/9] Add configure check to test if gcc supports attribute ifunc.
- Authentication-results: sourceware.org; auth=none
- References: <1470667145-18563-1-git-send-email-stli@linux.vnet.ibm.com>
On 08/08/2016 09:38 AM, Stefan Liebler wrote:
> This patch adds a configure check to test if gcc supports attribute ifunc.
> The support can either be enabled in <gcc-src>/gcc/config.gcc for one
> architecture in general by setting default_gnu_indirect_function variable to yes
> or by configuring gcc with --enable-gnu-indirect-function.
>
> The next patch rewrites libc_ifunc macro to use gcc attribute ifunc instead
> of inline assembly to generate the IFUNC symbols due to false debuginfo.
>
> If gcc does not support attribute ifunc and glibc is configured with
> --enable-multi-arch then configure will abort with an error message.
> If --enable-multi-arch is not given then configure will silently
> disable multi-arch support.
>
> ChangeLog:
>
> * configure.ac: Add check if gcc supports attribute ifunc feature.
> * configure: Regenerated.
One more hiccup after trying out this patch. pt-vfork.c mandates ifunc
on most (all?) targets using nptl. It seems configure needs to mandate
this support on any target using nptl.